53 o Dr. C. R. Alder Wright. [Feb. 2, 



IV. " On Certain Ternary Alloys. Part VII. Alloys containing 

 Zinc, together with Lead (or Bismuth) and Cadmium (or 

 Antimony)." By C. R. ALDER WRIGHT, D.Sc., F.R.S., 

 Lecturer on Chemistry and Physics in St. Mary's Hospital 

 Medical School. Received January 5, 1893. 



In the previous six papers* it has been shown that when silver is 

 substituted for tin as " solvent " metal the critical curve deduced is 

 uniformly raised, whether the two immiscible metals employed be 

 lead and zinc, bismuth and zinc, lead and aluminium, or bismuth and 

 aluminium; it was thought desirable to examine similarly the effects 

 of other solvent metals, more especially cadmium and antimony, direct 

 experiments having shown that these metals respectively are miscible 

 in all proportions whilst molten with either lead, bismuth, or zinc ; 

 although in some cases more or less marked segregation of the metals 

 from one another takes place on cooling so that solidification commences. 

 Accordingly the experiments described below were made with zinc as 

 lighter immiscible metal ; but on substituting aluminium for zinc, so 

 as to prepare ternary alloys containing lead (or bismuth), aluminium, 

 and cadmium (or antimony), it was found that the close analogy 

 between zinc and aluminium found in Part VI to subsist in alloys 

 containing one or other of these metals along with lead (or bismuth) 

 and tin (or silver) breaks down with these other combinations ; in 

 the case of the alloys where cadmium is the solvent metal, because 

 molten cadmium and aluminium (contrary to the usual statements in 

 the text-books) are not completely miscible together, like zinc and 

 aluminium, but behave as lead and aluminium, or bismuth and 

 aluminium, the heavier metal dissolving only a fe*v tenths per cent, 

 of aluminium, whilst this latter dissolves only some 2 or 3 per cents, 

 of the other metal; and in the case of the alloys where antimony is 

 the solvent, because aluminium and antimony combine together to 

 form a most remarkable compound, represented by the formula 

 AlSb,f which possesses a melting point higher by upwards of 340 C. 

 than that of the least fusible of its constituents ; thus, whilst an- 

 timony melts at about 432 C., and aluminium at below 700 C. 

 (varying somewhat according to its purity or otherwise), the com- 

 pound AlSb appears (from observations kindly made for the author 

 by Professor Roberts-Austen with the Le Chatelier pyrometer) to have 

 a solidifying point close to that of gold, viz., 1045. The effect of the 



* Part I, ' Eoy. Soc. Proc.,' vol. 45, p. 461 ; Part II, vol. 48, p. 25 ; Part III, 

 vol. 49, p. 156 ; Part IV, vol. 49, p. 174 ; Part V, vol. 50, p. 372 ; Part VI, vol. 52, 

 p. 11. 



t ' Journal Society of Chemical Industry,' 1892, p. 492. 



